There are 2 aspects to this.

  1. What you are allowed to do
  2. What you should do

Whether you are allowed to add so many ad units from so many networks?

Yes. It is your website. You can add as many ad units as you want. Check the policies of those ad networks, if there is no restriction on the number of ad units to be used on the pages, you can add it.

Whether you should do it?

NO.

When you try to monetize the content of the blog, remeber that your website visitors are coming for your content and not for the ads.

Keeping too many ad units on the same page will annoy the users. This will result in poor user experience and high bounce-rate. Search Engines give lower preference to pages having high bounce rate. Keep maximum 3 ad units on a particular page.

Also, AdSense or any other monetisation platforms are not reliable sources for earning money. If you search on Google, you will find so many ad publishers talking/complaining about getting blocked by these platforms.

What will you do if you get blocked by these platforms?

You need to use other ways to monetise your content.

  1. Sell ad spaces – If your blog is talking about a niche market, you can sell the ad spaces to the big players in that industry. Use analytics and demographic data of website visitors to sell the ad spaces.
  2. Newsletter signup – Ask the users to signup for your newsletter. Keep a slot of your newsletter for ad spaces and sell those spaces to advertisers.
  3. Affiliate ad units – You can join various affiliate programs. E.g. You can join Bluehost affiliate program and put their ads on your blog. If someone clicks on the ad and makes a purchase on BlueHost.com, you will earn a good commission from BlueHost.

There are so many other ways to monetise your content.

Or you can search about it on Google.

Important things to remember:

  1. Focus on the content that provides value to the readers.
  2. Do not rely on just one monitization method or platform.
  3. Do not keep too many ads on the page, it causes poor user experience which increases the bounce rate and decreases your ranking in Search Engines.